cleanup, more comments, support old backup format

Author: alubennikova

contrib/pg_probackup/backup.c

@@ -1132,6 +1132,9 @@ file_size(const char *file)
  * Find corresponding file in previous backup.
  * Compare generations and return true if we don't need full copy
  * of the file, but just part of it.
+ *
+ * skip_size - size of the file in previous backup. We can skip it
+ *			   and copy just remaining part of the file.
  */
 bool
 backup_compressed_file_partially(pgFile *file, void *arg, size_t *skip_size)
@@ -1423,7 +1426,7 @@ add_files(parray *files, const char *root, bool add_root, bool is_pgdata)
 		{
 			if (current.backup_mode == BACKUP_MODE_DIFF_PAGE)
 				elog(ERROR, "You can't use PAGE mode backup with compressed tablespace.\n"
-							"Try PTRACK mode instead.");
+							"Try FULL or PTRACK mode instead.");
 			continue;
 		}
 
@@ -1776,18 +1779,19 @@ FileMap* cfs_mmap(int md)
 {
 	FileMap* map;
 #ifdef WIN32
-    HANDLE mh = CreateFileMapping(_get_osfhandle(md), NULL, PAGE_READWRITE, 
+    HANDLE mh = CreateFileMapping(_get_osfhandle(md), NULL, PAGE_READWRITE,
 								  0, (DWORD)sizeof(FileMap), NULL);
-    if (mh == NULL) { 
+    if (mh == NULL)
         return (FileMap*)MAP_FAILED;
-    }
-    map = (FileMap*)MapViewOfFile(mh, FILE_MAP_ALL_ACCESS, 0, 0, 0); 
+
+    map = (FileMap*)MapViewOfFile(mh, FILE_MAP_ALL_ACCESS, 0, 0, 0);
 	CloseHandle(mh);
-    if (map == NULL) { 
+    if (map == NULL)
         return (FileMap*)MAP_FAILED;
-    }
+
 #else
-	map = (FileMap*)mmap(NULL, sizeof(FileMap), PROT_WRITE | PROT_READ, MAP_SHARED, md, 0);
+	map = (FileMap*)mmap(NULL, sizeof(FileMap),
+						 PROT_WRITE | PROT_READ, MAP_SHARED, md, 0);
 #endif
 	return map;
 }

contrib/pg_probackup/data.c

@@ -412,7 +412,10 @@ backup_data_file(const char *from_root, const char *to_root,
 	return true;
 }
 
-
+/*
+ * Restore compressed file that was backed up partly.
+ * 
+ */
 static void
 restore_file_partly(const char *from_root,const char *to_root, pgFile *file)
 {
@@ -491,7 +494,8 @@ restore_file_partly(const char *from_root,const char *to_root, pgFile *file)
 		write_size += read_len;
 	}
 
-	elog(NOTICE, "restore_file_partly(). write_size %lu, file->write_size %lu", write_size, file->write_size);
+// 	elog(LOG, "restore_file_partly(). %s write_size %lu, file->write_size %lu",
+// 			   file->path, write_size, file->write_size);
 
 	/* update file permission */
 	if (chmod(to_path, file->mode) == -1)
@@ -518,7 +522,8 @@ restore_compressed_file(const char *from_root,
 	else if (file->is_partial_copy == 1)
 		restore_file_partly(from_root, to_root, file);
 	else
-		elog(ERROR, "restore_compressed_file()");
+		elog(ERROR, "restore_compressed_file(). Unknown is_partial_copy value %d",
+					file->is_partial_copy);
 }
 
 /*
@@ -537,20 +542,18 @@ restore_data_file(const char *from_root,
 	BackupPageHeader	header;
 	BlockNumber			blknum;
 
-	/* If the file is not a datafile, just copy it. */
 	if (!file->is_datafile)
 	{
+		/*
+		 * If the file is not a datafile and not compressed file,
+		 * just copy it.
+		 */
 		if (file->generation == -1)
-		{
 			copy_file(from_root, to_root, file);
-			return;
-		}
 		else
-		{
-			/* It is compressed file */
 			restore_compressed_file(from_root, to_root, file);
-			return;
-		}
+
+		return;
 	}
 
 	/* open backup mode file for read */
@@ -808,6 +811,11 @@ copy_file(const char *from_root, const char *to_root, pgFile *file)
 	return true;
 }
 
+/*
+ * Save part of the file into backup.
+ * skip_size - size of the file in previous backup. We can skip it
+ *			   and copy just remaining part of the file
+ */
 bool
 copy_file_partly(const char *from_root, const char *to_root,
 				 pgFile *file, size_t skip_size)
@@ -841,6 +849,7 @@ copy_file_partly(const char *from_root, const char *to_root,
 		snprintf(to_path, lengthof(to_path), "%s/tmp", backup_path);
 	else
 		join_path_components(to_path, to_root, file->path + strlen(from_root) + 1);
+
 	out = fopen(to_path, "w");
 	if (out == NULL)
 	{
@@ -863,7 +872,10 @@ copy_file_partly(const char *from_root, const char *to_root,
 		elog(ERROR, "cannot seek %lu of \"%s\": %s",
 				skip_size, file->path, strerror(errno));
 
-	/* copy content and calc CRC */
+	/*
+	 * copy content
+	 * NOTE: Now CRC is not computed for compressed files now.
+	 */
 	for (;;)
 	{
 		if ((read_len = fread(buf, 1, sizeof(buf), in)) != sizeof(buf))
@@ -919,8 +931,10 @@ copy_file_partly(const char *from_root, const char *to_root,
 			 strerror(errno_tmp));
 	}
 
+	/* add meta information needed for recovery */
 	file->is_partial_copy = 1;
-	elog(NOTICE, "copy_file_partly(). %s file->write_size %lu", to_path, file->write_size);
+
+//	elog(LOG, "copy_file_partly(). %s file->write_size %lu", to_path, file->write_size);
 
 	fclose(in);
 	fclose(out);

contrib/pg_probackup/dir.c

@@ -550,8 +550,8 @@ dir_read_file_list(const char *root, const char *file_txt)
 	{
 		char			path[MAXPGPATH];
 		char			type;
-		int				generation;
-		int				is_partial_copy;
+		int				generation = -1;
+		int				is_partial_copy = 0;
 		unsigned long	write_size;
 		pg_crc32		crc;
 		unsigned int	mode;	/* bit length of mode_t depends on platforms */
@@ -565,9 +565,17 @@ dir_read_file_list(const char *root, const char *file_txt)
 			&tm.tm_hour, &tm.tm_min, &tm.tm_sec,
 			&generation, &is_partial_copy) != 13)
 		{
-			elog(ERROR, "invalid format found in \"%s\"",
-				file_txt);
+			/* Maybe the file_list we're trying to recovery is in old format */
+			if (sscanf(buf, "%s %c %lu %u %o %d-%d-%d %d:%d:%d",
+				path, &type, &write_size, &crc, &mode,
+				&tm.tm_year, &tm.tm_mon, &tm.tm_mday,
+				&tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 11)
+			{
+				elog(ERROR, "invalid format found in \"%s\"",
+					file_txt);
+			}
 		}
+
 		if (type != 'f' && type != 'F' && type != 'd' && type != 'l')
 		{
 			elog(ERROR, "invalid type '%c' found in \"%s\"",

contrib/pg_probackup/pg_probackup.h

@@ -25,7 +25,6 @@
 #include "storage/block.h"
 #include "storage/checksum.h"
 
-#include "portability/mem.h"
 #ifndef WIN32
 #include <sys/mman.h>
 #endif
@@ -183,7 +182,12 @@ typedef union DataPage
 } DataPage;
 
 
-typedef struct 
+/*
+ * This struct definition mirrors one from cfs.h,
+ * but doesn't use atomic variables, since they are not allowed in
+ * frontend code.
+ */
+typedef struct
 {
 	uint32 physSize;
 	uint32 virtSize;

contrib/pg_probackup/validate.c

@@ -199,6 +199,8 @@ pgBackupValidateFiles(void *arg)
 			elog(ERROR, "interrupted during validate");
 
 		/* skipped backup while differential backup */
+		/* NOTE We don't compute checksums for compressed data,
+		 * so skip it too */
 		if (file->write_size == BYTES_INVALID
 			|| !S_ISREG(file->mode)
 			|| file->generation != -1)